Friday, June 28, 2013

The Harm-Made Mind

Here is a fascinating bit from Daniel Wegner and his collaborators. (I cite Wegner extensively in my "I-Illusion" web-lecture in introductory lectures sections of the left had column of this web page.)
People often think that something must have a mind to be part of a moral interaction. However, the present research suggests that minds do not create morality but that morality creates minds. In four experiments, we found that observing intentional harm to an unconscious entity—a vegetative patient, a robot, or a corpse—leads to augmented attribution of mind to that entity. A fifth experiment reconciled these results with extant research on dehumanization by showing that observing the victimization of conscious entities leads to reduced attribution of mind to those entities. Taken together, these experiments suggest that the effects of victimization vary according to victims’ preexisting mental status and that people often make an intuitive cognitive error when unconscious entities are placed in harm’s way. People assume that if apparent moral harm occurs, then there must be someone there to experience that harm—a harm-made mind. These findings have implications for political policies concerning right-to-life issues.

Wednesday, June 26, 2013

Are you married? Did you meet on-line or off-line?

Interesting bit from Cacioppo et al.
Marital discord is costly to children, families, and communities. The advent of the Internet, social networking, and on-line dating has affected how people meet future spouses, but little is known about the prevalence or outcomes of these marriages or the demographics of those involved. We addressed these questions in a nationally representative sample of 19,131 respondents who married between 2005 and 2012. Results indicate that more than one-third of marriages in America now begin on-line. In addition, marriages that began on-line, when compared with those that began through traditional off-line venues, were slightly less likely to result in a marital break-up (separation or divorce) and were associated with slightly higher marital satisfaction among those respondents who remained married. Demographic differences were identified between respondents who met their spouse through on-line vs. traditional off-line venues, but the findings for marital break-up and marital satisfaction remained significant after statistically controlling for these differences. These data suggest that the Internet may be altering the dynamics and outcomes of marriage itself.

Tuesday, June 25, 2013

Brain science backlash, throwing out the baby with the bathwater.

A recent NYTimes Op-Ed piece by David Brooks' ("Beyond the Brain") references the recent book "“Brainwashed: The Seductive Appeal of Mindless Neuroscience.” a book that appropriately notes some of the limitations of zealous over interpretation of brain imaging data but also includes some facile straw man arguments. Brooks kind of loses it in his comment:
It is probably impossible to look at a map of brain activity and predict or even understand the emotions, reactions, hopes and desires of the mind...there appears to be no dispersed pattern of activation that we can look at and say, “That person is experiencing hatred."
These sentiments are simply wrong, and I thought, rather than rambling on myself, I would point interested readers to two cogent commentaries on the recent anti-brain science surge, one in The New Yorker blog posted by Gary Marcus, the other in The Neurocritic blog.

Monday, June 24, 2013

Paternal stress changes stress axis in offspring

A study from Bale and colleagues shows that stress on preadolescent and adult male mice induces an epigenetic mark in their sperm that reprogramms their offspring's hypothalamic-pituitary-adrenal (HPA) axis, the brain regions that governs responses to stress. Offspring from paternal stress groups displayed significantly blunted levels of the stress hormone corticosterone -- in humans, it's cortisol -- in response to stress. It is curious that both male and female offspring had abnormally low reactivity to stress. Perhaps this reduced physiological stress response may reflect some adaptive evolutionary benefit passed on to offspring to ensure survival in what is expected to be a more stressful environment.
Neuropsychiatric disease frequently presents with an underlying hyporeactivity or hyperreactivity of the HPA stress axis, suggesting an exceptional vulnerability of this circuitry to external perturbations. Parental lifetime exposures to environmental challenges are associated with increased offspring neuropsychiatric disease risk, and likely contribute to stress dysregulation. While maternal influences have been extensively examined, much less is known regarding the specific role of paternal factors. To investigate the potential mechanisms by which paternal stress may contribute to offspring hypothalamic–pituitary–adrenal (HPA) axis dysregulation, we exposed mice to 6 weeks of chronic stress before breeding. As epidemiological studies support variation in paternal germ cell susceptibility to reprogramming across the lifespan, male stress exposure occurred either throughout puberty or in adulthood. Remarkably, offspring of sires from both paternal stress groups displayed significantly reduced HPA stress axis responsivity. Gene set enrichment analyses in offspring stress regulating brain regions, the paraventricular nucleus (PVN) and the bed nucleus of stria terminalis, revealed global pattern changes in transcription suggestive of epigenetic reprogramming and consistent with altered offspring stress responsivity, including increased expression of glucocorticoid-responsive genes in the PVN. In examining potential epigenetic mechanisms of germ cell transmission, we found robust changes in sperm microRNA (miR) content, where nine specific miRs were significantly increased in both paternal stress groups. Overall, these results demonstrate that paternal experience across the lifespan can induce germ cell epigenetic reprogramming and impact offspring HPA stress axis regulation, and may therefore offer novel insight into factors influencing neuropsychiatric disease risk.

Saturday, June 22, 2013

Paper is not dead...

Sorry to spam you, but particularly after yesterday's post about smartphone apps I thought this was hysterical.

Friday, June 21, 2013

More on smartphone brain training apps.

This post is just a quickie pointer to update the series of posts I have done on smart phone or PC apps that give your brain a workout.  It reviews several current products.  I try each new iteration for a bit,  but then fade because I am phobic about "competing" with myself or anyone else and also get concerned that my scores are not improving fast enough.  I didn't grow up in a video game playing world, and they feel too much like hard work - I like things that feel easy with the skills I have,  like learning a new piano score. 

Wednesday, June 19, 2013

Neuroimaging our self esteem - be happy!

There are more papers coming out on brain correlates of whatever aspect of our behaviors you care to name than anyone could possibly keep up with. I have the ‘my eyes glaze over’ experience in just scanning tables of contents of the relevant journals. Occasionally an item pops out that grabs my attention, such as this one (open access) on imaging brain correlates of self esteem. The drums continue to beat (see this book review) on how important a positive self image and an "Up" attitude are for health and longevity. Maybe someone will develop some kind of magnetic zapper that we can shoot ourselves up with whenever whenever we are feeling like a piece of …... 
Although neuroimaging studies strongly implicate the medial prefrontal cortex (ventral and dorsal), cingulate gyrus (anterior and posterior), precuneus and temporoparietal cortex in mediating self-referential processing (SRP), little is known about the neural bases mediating individual differences in valenced SRP, that is, processes intrinsic to self-esteem. This study investigated the neural correlates of experimentally engendered valenced SRP via the Visual–Verbal Self-Other Referential Processing Task in 20 women with fMRI. Participants viewed pictures of themselves or unknown other women during separate trials while covertly rehearsing ‘I am’ or ‘She is’, followed by reading valenced trait adjectives, thus variably associating the self/other with positivity/negativity. Response within dorsal and ventral medial prefrontal cortex, cingulate cortex and left temporoparietal cortex varied with individual differences in both pre-task rated self-descriptiveness of the words, as well as task-induced affective responses. Results are discussed as they relate to a social cognitive and affective neuroscience view of self-esteem.

.... stimulus presentations were blocked in terms of the conditions Reference (Self vs Other, i.e. photographs) and Valence (words), creating four trial types: self-negative (S-N), self-positive (S-P), other-negative (O-N) and other-positive (O-P). Participants were not instructed that they ‘should try to press the buttons as fast as possible’ as is often done in social cognition experiments. In contrast, participants were instructed only to press the buttons ‘so that we can assess afterwards whether you are paying attention to and completing the task’. This passive orientation was intended to focus attention towards introspection and interoception with participants reminded repeatedly of the importance of ‘paying close attention to how you are feeling throughout the different parts of the task’.

Tuesday, June 18, 2013

Young blood makes younger hearts (and brains) - also, aging resistant brains

I've previously mentioned work showing that providing young blood to an older brain can be beneficial, and now want to note work by Loffredo et al. that shows that exposure to a young circulation reverses age-related cardiac hypertrophy, which is a prominent feature of age-related diatolic heart failure. The TGFβ family member GDF11 appears to be the crucial circulating factor that declines with age; restoring GDF11 to youthful levels reverses age-related cardiac hypertrophy. 

Also, relevant to aging, I might note a longitudinal study by Pudas et al. comparing MRI data from elderly people most successful in preserving episodic memory and ability on paired association tasks with measurements on average contemporaries. The results suggest that successful cognitive aging is associated with preservation of the responsiveness of the hippocampus and prefrontal cortex.

Monday, June 17, 2013

Heart rate variability, ANS aging - a new device from "Phyode" - therapeutic agent or scam??

I want to put in this post a comment by reader "Andre" on my June 11 post ("Changes as an autonomic nervous system ages 11 years - The "Wild Divine" is a bit less wild.", along with my response.
Last week I backed a Kickstarter project from Phyode called the W/Me (, a smartwatch that uses HRV and "ANS Age" as its primary markers for assessing the user's "mental state". I couldn't find a research precedent for using ANS aging for this purpose until your post came up in a Google search. Do you think Phyode's methodology is valid?
My response on looking at the website:
This is a very slick presentation, and looks like a potentially interesting product...If it were not for the fact that its development appears to be limited to Android products (i.e. no iPhone App)[NOTE! 10/22/13 - comment below says I'm wrong, it is for iPhone, not Android, my bad..] I would probably try it out when it is sold (There are, by the way several iPhone apps that do heart rate, HRV, etc.).....BUT, there are no pointers to basic scientific references on heart rate variability, ANS age, how it can be therapeutically altered in a beneficial way, or how his device would be used to do that. The FAQ section at the end of the web page with what look like links to such items as "What is HRV?" don't link to anything!! The Phyode "Full bio and links" doesn't yield anything significant! I would be interested in seeing something a bit more substantial from the people in the flashy video presentations (all appear to be 20-somethings, by the way). I don't want to play the complete nasty guy here, because a lot of effort went into the slick videos and description, and they look plausible, but what assures us that the fund raising "Back this project" (minimum donation $1.00) is not a scam? Does the Kickstarter cloud funding site that hosts this webpage have any quality controls or review criteria?? The "report this site to Kickstarter" link takes you to a page that requires you to join or be member of Kickstarter, and I'm not inclined to take that much time on this....

Carrying human (and mouse) babies reduces their crying and heart rate.

Esposito et al. present some really nice observations. They demonstrate for the first time that the infant calming response to maternal carrying is a coordinated set of central, motor, and cardiac regulations and is a conserved component of mammalian mother-infant interactions. You should watch the video.

-Maternal carrying reduces crying, body movement, and heart rate of infants
-In mice, a similar set of calming responses is observed during carrying
 -Mouse calming response requires proprioception and somatosensation
 -The calming responses in infants function to increase maternal carrying efficacy
Here we show a novel set of infant cooperative responses during maternal carrying. Infants under 6 months of age carried by a walking mother immediately stopped voluntary movement and crying and exhibited a rapid heart rate decrease, compared with holding by a sitting mother. Furthermore, we identified strikingly similar responses in mouse pups as defined by immobility and diminished ultrasonic vocalizations and heart rate. Using pharmacologic and genetic interventions in mouse pups, we identified the upstream and downstream neural systems regulating the calming response. Somatosensory and proprioceptive input signaling are required for induction, and parasympathetic and cerebellar functions mediate cardiac and motor output, respectively. The loss of the calming response hindered maternal rescue of the pups, suggesting a functional significance for the identified calming response.

Friday, June 14, 2013

Our memory can be selectively rewritten during its reconsolidation.

Chan and LaPaglia make an interesting observation in humans that had previously only been reported in animal studies. We can mess with an existing declarative memory of an event after that memory has been reactivated, if during its reconsolidation we are presented with changes that target and change some details of the original memory. Reactivated memories are vulnerable only to interference that specifically targets the existing memories. This work provides yet another example of how eye witness testimony of the sort used in legal proceedings can become unreliable.
During the past decade, a large body of research has shown that memory traces can become labile upon retrieval and must be restabilized. Critically, interrupting this reconsolidation process can abolish a previously stable memory. Although a large number of studies have demonstrated this reconsolidation associated amnesia in nonhuman animals, the evidence for its occurrence in humans is far less compelling, especially with regard to declarative memory. In fact, reactivating a declarative memory often makes it more robust and less susceptible to subsequent disruptions. Here we show that existing declarative memories can be selectively impaired by using a noninvasive retrieval–relearning technique. In six experiments, we show that this reconsolidation-associated amnesia can be achieved 48 h after formation of the original memory, but only if relearning occurred soon after retrieval. Furthermore, the amnesic effect persists for at least 24 h, cannot be attributed solely to source confusion and is attainable only when relearning targets specific existing memories for impairment. These results demonstrate that human declarative memory can be selectively rewritten during reconsolidation.

Thursday, June 13, 2013

Antonin Scalia Does Not Believe in Molecular Biology

Thanks to my son Jon for pointing this out to me.

Private behaviors from public records...

The exposure of the PRISM surveillance system by Edward Snowden gave me a sort of "So what else is new?" reaction... I thought we knew this unfortunate stuff was happening, particularly in view of numerous academic articles in the vein of the following from Kosinski et al.:
We show that easily accessible digital records of behavior, Facebook Likes, can be used to automatically and accurately predict a range of highly sensitive personal attributes including: sexual orientation, ethnicity, religious and political views, personality traits, intelligence, happiness, use of addictive substances, parental separation, age, and gender. The analysis presented is based on a dataset of over 58,000 volunteers who provided their Facebook Likes, detailed demographic profiles, and the results of several psychometric tests. The proposed model uses dimensionality reduction for preprocessing the Likes data, which are then entered into logistic/linear regression to predict individual psychodemographic profiles from Likes. The model correctly discriminates between homosexual and heterosexual men in 88% of cases, African Americans and Caucasian Americans in 95% of cases, and between Democrat and Republican in 85% of cases. For the personality trait “Openness,” prediction accuracy is close to the test–retest accuracy of a standard personality test. We give examples of associations between attributes and Likes and discuss implications for online personalization and privacy.

Tuesday, June 11, 2013

Changes as an autonomic nervous system ages 11 years - The "Wild Divine" is a bit less wild.

Just after I retired from being a Univ. of Wisconsin department chair in 2001 I bought a set of finger sensors that fit on one's three middle fingers to report skin conductance and heartbeat to a PC or MAC via an A/D converter. These were part of a package with several CDs that installed a new age game on the computer that lead you through a rich environment of classical greek temples and waterfalls, attended by soothing music, that presented tasks in which you dinked with your own heart rate variability and sympathetic (arousing)/parasympathetic (calming) balance, going alternatively through periods of calm and arousal. I thought it was a hoot, and took the time to go through the "Journey to Wild Divine: passage" and "Journey to Wild Divine: Wisdom Quest."

Some of the current incarnations of these programs have moved to web browsers. Over the years a number of heavy weight new age gurus have signed on with their wares - Deepak Chopra, Dean Ornish, and Andrew Weil (Weil was in my Harvard graduating class...I'm tempted, but I won't burden you with my jaded opinion of this class of entrepreneurs, particularly Mr. Chopra.)

The main point of this post is note my experience on pulling out the finger sensors after 11 years trying the same exercises in their new presentation. What's the difference when this 71 year old tries the same manipulations of calm and arousal that the 60 year old played with with 11 years earlier? In a nutshell, I have less command over heart rate variability, which is lower, as the swings between calm and arousal have less amplitude.

And indeed, this fits with the literature on changes in the autonomic nervous system that occur on aging. If you simply do a google search for "autonomic nervous system and aging" numerous references appear that document how healthy aging is associated with lowered heart rate variability, elevated basal sympathetic nervous activity, and reduction of overall autonomic reactivity of sympathetic and parasympathetic nervous systems. Here is a very recent review, from which I pass on one figure:

Schematic of proposed features associated with the imbalance in the autonomic nervous system during aging. During aging there is a shift in the balance of the autonomic nervous system (ANS) towards the sympathetic nervous system (SNS). This may be influenced by circulating or local brain levels of angiotensin (Ang) II and leptin. The lower activity of the parasympathetic nervous system (PSNS) is proposed to result at least in part from an age-related decline in Angiotensin-(1–7). Lower Angiotensin-(1–7) and higher Ang II or leptin in the brain medulla would predispose to a decline in baroreceptor reflex sensitivity (BRS) for control of heart rate and heart rate variability (HRV), both of which are associated with aging. Moreover, impairments in BRS and HRV can contribute to target organ damage, including metabolic dysfunction, with or without an increase in blood pressure. 

If you're inclined, like Mr. Dylan Thomas, to not "go gently into that good night" you can find numerous sources (example here) on slowing these aging changes, usually by some sort of physical movement or stimulation.

Monday, June 10, 2013

Preventing Alzheimer’s associated brain cell atrophy with B vitamin treatment.

I pass this on because it seems like a very striking result. Douaud et al. find that high-dose B-vitamin treatment (folic acid 0.8 mg, vitamin B6 20 mg, vitamin B12 0.5 mg) causes a 7-fold decrease in cerebral atrophy of nerve cell areas most vulnerable to the Alzheimer's process over a 2-year period in a group of elderly subjects with increased dementia risk. (For comparison, Centrum Silver 50+ has Folic Acid 0.4 mg, Vitamin B6 3 mg, and Vitamin B12 0.025 mg.) The supplements decrease plasma levels of one of the bad players in the Alzheimer's story, homocysteine. (Homocysteine is a homologue of the amino acid cysteine,and can be recycled into methionine or converted into cysteine with the aid of B-vitamins.) Here's the abstract:
Is it possible to prevent atrophy of key brain regions related to cognitive decline and Alzheimer’s disease (AD)? One approach is to modify nongenetic risk factors, for instance by lowering elevated plasma homocysteine using B vitamins. In an initial, randomized controlled study on elderly subjects with increased dementia risk (mild cognitive impairment according to 2004 Petersen criteria), we showed that high-dose B-vitamin treatment (folic acid 0.8 mg, vitamin B6 20 mg, vitamin B12 0.5 mg) slowed shrinkage of the whole brain volume over 2 y. Here, we go further by demonstrating that B-vitamin treatment reduces, by as much as seven fold, the cerebral atrophy in those gray matter (GM) regions specifically vulnerable to the AD process, including the medial temporal lobe. In the placebo group, higher homocysteine levels at baseline are associated with faster GM atrophy, but this deleterious effect is largely prevented by B-vitamin treatment. We additionally show that the beneficial effect of B vitamins is confined to participants with high homocysteine (above the median, 11 µmol/L) and that, in these participants, a causal Bayesian network analysis indicates the following chain of events: B vitamins lower homocysteine, which directly leads to a decrease in GM atrophy, thereby slowing cognitive decline. Our results show that B-vitamin supplementation can slow the atrophy of specific brain regions that are a key component of the AD process and that are associated with cognitive decline. Further B-vitamin supplementation trials focusing on elderly subjets with high homocysteine levels are warranted to see if progression to dementia can be prevented.
Here is one figure from the paper:

B-vitamin treatment significantly reduces regional loss of gray matter. (A) Brain regions in blue demonstrate where B-vitamin treatment significantly reduces GM loss over the 2-y period. All blue areas correspond to regions of significant loss in placebo and known to be vulnerable in AD. (B) Percentage of GM loss for the 156 participants over the 2-y period, averaged across those brain regions that showed significant effect of B vitamins: placebo group (red triangles) had an average loss of 3.7% (±3.7), whereas the B-vitamin group (green circles) showed a loss of 0.5% (±2.9).

Sunday, June 09, 2013

Visions of our high-tech future: Julian Assange, Jaron Lanier, et al. on Google, Siren servers and the banality of ‘Don’t Be Evil’

The book by Google's Eric Schmidt and Jared Cohen, "The New Digital Age" is a rosy scenario of our high-tech future that many have found a bit creepy and chilling. Since our techie surround will anticipate and take care of our every movement, it seems like we can just sign off and go along for the ride (turning in mental vegetables in the process? …and letting the rule of 'use it or lose it' do it's work on our poor brains?). Also, is it more than a coincidence that at roughly the same time as Schmidt's messianic book is appearing, the movie “The Internship,” a two-hour commercial for GoogleWorld masquerading as an aspirational buddy comedy, also appears in the movie theaters? (You might note this caustic review of the movie.)

Trying to set aside my bias, generated by extensive negative press comments on the behaviors of Wiki-Leaks' Julian Assange, I found his piece in the New York Times on the Schmidt and Cohen book to have some savory and choice screeds. A partial sampling:
“The New Digital Age” is, beyond anything else, an attempt by Google to position itself as America’s geopolitical visionary — the one company that can answer the question “Where should America go?” It is not surprising that a respectable cast of the world’s most famous warmongers has been trotted out to give its stamp of approval to this enticement to Western soft power. The acknowledgments give pride of place to Henry Kissinger, who along with Tony Blair and the former C.I.A. director Michael Hayden provided advance praise for the book.
…“Progress” is driven by the inexorable spread of American consumer technology over the surface of the earth. Already, every day, another million or so Google-run mobile devices are activated. Google will interpose itself, and hence the United States government, between the communications of every human being not in China (naughty China). Commodities just become more marvelous; young, urban professionals sleep, work and shop with greater ease and comfort; democracy is insidiously subverted by technologies of surveillance, and control is enthusiastically rebranded as “participation”; and our present world order of systematized domination, intimidation and oppression continues, unmentioned, unafflicted or only faintly perturbed.
This book is a balefully seminal work in which neither author has the language to see, much less to express, the titanic centralizing evil they are constructing. “What Lockheed Martin was to the 20th century,” they tell us, “technology and cybersecurity companies will be to the 21st.” Without even understanding how, they have updated and seamlessly implemented George Orwell’s prophecy. If you want a vision of the future, imagine Washington-backed Google Glasses strapped onto vacant human faces — forever. Zealots of the cult of consumer technology will find little to inspire them here, not that they ever seem to need it. But this is essential reading for anyone caught up in the struggle for the future, in view of one simple imperative: Know your enemy.
If you want to read what I think is one of the best articles I have seen so far on the unfortunate consequences of our digital universe and possible cures, check out Jaron Lanier's article "Fixing the Digital Economy." It describes the concentration of power and income in the small sliver of the population that designs and runs the massive servers (Siren servers) that analyze different sectors of our lives to minimize their risk and maximize their profits.
Even friendly, consumer-facing Siren Servers ultimately depend on spreading costs to the larger society. Siren Servers can function profitably only if people aren’t paid for the data that is used to calculate their statistical schemes.
Siren Servers drive apart our identities as consumers and workers. In some cases, causality is apparent: free music downloads are great but throw musicians out of work. Free college courses are all the fad, but tenured professorships are disappearing. Free news proliferates, but money for investigative and foreign reporting is drying up. One can easily see this trend extending to the industries of the future, like 3-D printing and renewable energy.
Lanier suggests that we need to nurture a middle class that can thrive even in a highly automated society. One approach:
Institute a universal micropayment system. Keep track of where information came from. Pay people when information that exists because they exist turns out to be valuable, no matter what kind of information is involved or whether a person intended to provide it or not. Let the price be determined by markets.
Person-to-person information markets might lead to a simpler and clearer online world. Because our information systems are designed to initially forget who provided information, services like Google and Bing must constantly scrape the global network to reconstitute the context of data. Siren Servers know who links to your data, but you don’t.
EVEN today’s titanic Siren Servers would benefit from a more monetized information economy, because it would be a healthier-growing economy. The information economy cannot exhibit the long-term growth it ought to if information coming from ordinary people is forever declared to be off the books.
Skeptics sometimes reveal hidden and unfounded wells of elitism. These surface in comments like: “Most people wouldn’t contribute very much.” But there are already empirical hints to counter such pessimism.
In networks with a central point of control, like YouTube or the Apple Store, we do see a Horatio Alger pattern in the distribution of outcomes, where there are very few viable winners and an unbounded number of hopefuls. But in more directly and thickly connected networks like Facebook, we see people typically exposed to a large number of other people, rather than just a few stars. Therefore, if Facebook users paid one another, they would see a less elite distribution of economic benefits.
Another potential benefit of monetized information is to balance the power of government. When information is free, there is no cost to gathering information about citizens. I would like the government, or anyone else, to pay each person each time that person is tracked by a camera. The government should be able to use cameras for security purposes, but in a limited, not unbounded way. Similarly, candidates should not be able to win elections by having the best Siren Servers, but that’s only a problem if the information is free. Citizens should not lose the power of the purse.
As a final note, this Douthat piece regarding the recently revealed NSA snooping on citizens mentions the fact that the problem isn’t that the Internet has been penetrated by the surveillance state; it’s that the Internet, in effect, is a surveillance state.

Saturday, June 08, 2013

Penis size and male attractiveness - the most read article in The Proceedings of the National Academy!

I finally had to pass this on.... When I check out the table of contents for new issues of the Proceedings of the National Academy of Science, the right hand column of the page lists most read and most cited articles. For weeks I've been noting that the most read article is "Penis size interacts with body shape and height to influence male attractiveness." I've been trying to avoid it, assuming another evolutionary psychology fairy tale...but, I did have a look. To not deprive MindBlog readers of this gem, I pass on the abstract and one illustration:
Compelling evidence from many animal taxa indicates that male genitalia are often under postcopulatory sexual selection for characteristics that increase a male’s relative fertilization success. There could, however, also be direct precopulatory female mate choice based on male genital traits. Before clothing, the nonretractable human penis would have been conspicuous to potential mates. This observation has generated suggestions that human penis size partly evolved because of female choice. Here we show, based upon female assessment of digitally projected life-size, computer-generated images, that penis size interacts with body shape and height to determine male sexual attractiveness. Positive linear selection was detected for penis size, but the marginal increase in attractiveness eventually declined with greater penis size (i.e., quadratic selection). Penis size had a stronger effect on attractiveness in taller men than in shorter men. There was a similar increase in the positive effect of penis size on attractiveness with a more masculine body shape (i.e., greater shoulder-to-hip ratio). Surprisingly, larger penis size and greater height had almost equivalent positive effects on male attractiveness. Our results support the hypothesis that female mate choice could have driven the evolution of larger penises in humans. More broadly, our results show that precopulatory sexual selection can play a role in the evolution of genital traits.

Figures representing the most extreme height, shoulder-to-hip ratio, and penis size (±2 SD) (Right and Left) in comparison with the average (Center figure) trait values.

Friday, June 07, 2013

We can learn new information during sleep.

Arzi et al. have devised a nice demonstration of how we can learn new information during our sleep. They paired pleasant and unpleasant odors with different tones during sleep, and measured the subjects’ sniffs to tones alone when they were awake. Tones associated with pleasant smells produced stronger sniffs, and tones associated with disgusting smells produced weaker sniffs, despite the subjects’ lack of awareness of the learning process. The abstract:
During sleep, humans can strengthen previously acquired memories, but whether they can acquire entirely new information remains unknown. The nonverbal nature of the olfactory sniff response, in which pleasant odors drive stronger sniffs and unpleasant odors drive weaker sniffs, allowed us to test learning in humans during sleep. Using partial-reinforcement trace conditioning, we paired pleasant and unpleasant odors with different tones during sleep and then measured the sniff response to tones alone during the same nights' sleep and during ensuing wake. We found that sleeping subjects learned novel associations between tones and odors such that they then sniffed in response to tones alone. Moreover, these newly learned tone-induced sniffs differed according to the odor pleasantness that was previously associated with the tone during sleep. This acquired behavior persisted throughout the night and into ensuing wake, without later awareness of the learning process. Thus, humans learned new information during sleep.

Thursday, June 06, 2013

Childhood self-control predicts health, wealth, and public safety

An international collaboration between researchers at universities in the US, UK, Canada, and New Zealand has generated this study, which speaks for itself (The participants are members of the Dunedin Multidisciplinary Health and Development Study, which tracks the development of 1,037 individuals born in 1972–1973 in Dunedin, New Zealand.) :
Policy-makers are considering large-scale programs aimed at self-control to improve citizens’ health and wealth and reduce crime. Experimental and economic studies suggest such programs could reap benefits. Yet, is self-control important for the health, wealth, and public safety of the population? Following a cohort of 1,000 children from birth to the age of 32 y, we show that childhood self-control predicts physical health, substance dependence, personal finances, and criminal offending outcomes, following a gradient of self-control. Effects of children's self-control could be disentangled from their intelligence and social class as well as from mistakes they made as adolescents. In another cohort of 500 sibling-pairs, the sibling with lower self-control had poorer outcomes, despite shared family background. Interventions addressing self-control might reduce a panoply of societal costs, save taxpayers money, and promote prosperity.

Self-control gradient. Children with low self-control had poorer health (A), more wealth problems (B), more single-parent child rearing (C), and more criminal convictions (D) than those with high self-control.

Wednesday, June 05, 2013

MindBlog starts up some summer music - a Poulenc Valse

Calling it summer music is being optimistic... it is still very chilly in Madison. I'm starting to select some pieces for an early fall musical at my Twin Valley home in Middleton, WI. This Poulenc valse is fun and bouncy, and gives me an excuse to relearn the techie side of mixing good quality audio with video.

The chemistry of protecting our brains by fasting.

Actually, I'm making a big assumption in the post title... namely that the results obtained by Gräff et al. in mice would extrapolate to similar finding in the human brain. In several animal models, a reduced consumption of calories seems to protect against cognitive deficits such as memory loss, in addition to acting on many different cell types and tissues to slow down aging. They found that caloric restriction effectively delays the onset of neurodegeneration and preserves structural and functional synaptic plasticity as well as memory capacities. Fasting activates the expression and activity of the nicotinamide adenine dinucleotide (NAD)–dependent protein deacetylase SIRT1, a known promoter of neuronal life span. (A deacetylase is an enzyme that cleaves acetate groups - think acetic acid or vinegar - from their attachment to proteins.) Surprisingly, this effect of reduced consumption of calories is mimicked by a small-molecule SIRT1-activating compound. (Just in case you were curious, the compound is SRT3657 [tertα-butyl 4-((2-(2-(6-(2-(tert-butoxycarbonyl(methyl)amino)ethylamino)-2-butylpyrimidine-4- carboxamido)phenyl)thiazolo[5,4-b]pyridin-6-yl)methoxy)piperidine-1-carboxylate])!! Mice treated with this substance recapitulated the beneficial effects of caloric restriction against neurodegeneration-associated pathologies. If this mechanism also applies to humans, SIRT1 may represent an appealing pharmacological target against neurodegeneration. Here is the abstract:
Caloric restriction (CR) is a dietary regimen known to promote lifespan by slowing down the occurrence of age-dependent diseases. The greatest risk factor for neurodegeneration in the brain is age, from which follows that CR might also attenuate the progressive loss of neurons that is often associated with impaired cognitive capacities. In this study, we used a transgenic mouse model that allows for a temporally and spatially controlled onset of neurodegeneration to test the potentially beneficial effects of CR. We found that in this model, CR significantly delayed the onset of neurodegeneration and synaptic loss and dysfunction, and thereby preserved cognitive capacities. Mechanistically, CR induced the expression of the known lifespan-regulating protein SIRT1, prompting us to test whether a pharmacological activation of SIRT1 might recapitulate CR. We found that oral administration of a SIRT1-activating compound essentially replicated the beneficial effects of CR. Thus, SIRT1-activating compounds might provide a pharmacological alternative to the regimen of CR against neurodegeneration and its associated ailments.

Monday, June 03, 2013

Long-term improvement of brain function and cognition with brain stimulation and cognitive training.

A group of collaborators from the University of Oxford and Innsbruck Medical University have published an observation that simple transcranial random noise stimulation (TRNS) of the bilateral (both sides of the brain) dorsolateral prefrontal cortex (DLPFC) applied during cognitive training over five days causes improvement in learning and performance of complex arithmetic tasks (both calculation and drill leaning) that still persist on testing 6 months later. This correlates with long lasting oxygenated blood flow changes measured by near-infrared spectroscopy that suggests more efficient neurovascular coupling within the left DLPFC. Here is their complete abstract:
Noninvasive brain stimulation has shown considerable promise for enhancing cognitive functions by the long-term manipulation of neuroplasticity. However, the observation of such improvements has been focused at the behavioral level, and enhancements largely restricted to the performance of basic tasks. Here, we investigate whether transcranial random noise stimulation (TRNS) can improve learning and subsequent performance on complex arithmetic tasks. TRNS of the bilateral dorsolateral prefrontal cortex (DLPFC), a key area in arithmetic , was uniquely coupled with near-infrared spectroscopy (NIRS) to measure online hemodynamic responses within the prefrontal cortex. Five consecutive days of TRNS-accompanied cognitive training enhanced the speed of both calculation- and memory-recall-based arithmetic learning. These behavioral improvements were associated with defined hemodynamic responses consistent with more efficient neurovascular coupling within the left DLPFC. Testing 6 months after training revealed long-lasting behavioral and physiological modifications in the stimulated group relative to sham controls for trained and nontrained calculation material. These results demonstrate that, depending on the learning regime, TRNS can induce long-term enhancement of cognitive and brain functions. Such findings have significant implications for basic and translational neuroscience, highlighting TRNS as a viable approach to enhancing learning and high-level cognition by the long-term modulation of neuroplasticity.
For those of you who might well ask "How exactly is TRNS done?" here is a clip from their experimental procedures section. The photograph suggests a rather imposing device!:
Subjects received TRNS while performing the learning task each day. Two electrodes (5 cm × 5 cm) were positioned over areas of scalp corresponding to the DLPFC (F3 and F4, identified in accordance with the international 10-20 EEG procedure; see the figure). Electrodes were encased in saline-soaked synthetic sponges to improve contact with the scalp and avoid skin irritation. Stimulation was delivered by a DC-Stimulator-Plus device (DC-Stimulator-Plus, neuroConn). Noise in the high-frequency band (100–600Hz) was chosen as it elicits greater neural excitation than lower frequency stimulation. For the TRNS group, current was administered for 20 min, with 15 s increasing and decreasing ramps at the beginning and end, respectively, of each session of stimulation. In the sham group current was applied for 30 s after upward ramping and then terminated.